Liquid crystal display device having improved electrostatic discharge resistance

ABSTRACT

A liquid crystal display device includes a first substrate, a second substrate and liquid crystal. The first substrate includes pixel electrodes, a peripheral circuit and a dummy wiring. The peripheral circuit and the dummy wiring are provided outside a pixel area in which the pixel electrodes are arranged. The second substrate is opposed to the first substrate through the liquid crystal. The second substrate includes a translucent conductive film that is provided on an opposite side of the second substrate to a side where the liquid crystal is present. The dummy wiring is located on an outer peripheral side of the substrates than the peripheral circuit and is provided independently of the peripheral circuit in terms of circuit. The dummy wiring is grounded outside the first substrate.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/578,883, filed Jan. 19, 2022, which application is a continuation ofU.S. patent application Ser. No. 15/984,873, filed May 21, 2018, andissued as U.S. Pat. No. 11,256,151 on Feb. 22, 2022, which applicationis a continuation of U.S. patent application Ser. No. 15/078,170, filedMar. 23, 2016, and issued as U.S. Pat. No. 10,001,685 on Jun. 19, 2018,which application is a continuation application of U.S. patentapplication Ser. No. 14/447,243, filed Jul. 30, 2014, and issued as U.S.Pat. No. 9,335,594 on May 10, 2016, which application is a continuationapplication of U.S. patent application Ser. No. 12/003,455, filed Dec.26, 2007, and issued as U.S. Pat. No. 8,830,409 on Sep. 9, 2014, whichapplication claims priority to Japanese Priority Patent Application JP2006-352377 filed Dec. 27, 2006 in the Japan Patent Office on, theentire content of which is hereby incorporated by reference.

BACKGROUND Technical Field

The present invention relates to a liquid crystal display device and,more particularly, to improvement in electrostatic discharge resistanceof a liquid crystal display device.

Related Art

In a FFS (Fringe Field Switching) mode liquid crystal panel, a pixelelectrode and a common electrode, which control the alignment of liquidcrystal, both are provided in an element substrate, and these twoelectrodes are laminated through an insulating film. Of theseelectrodes, an upper layer electrode is provided with slits. A rubbingprocess is treated in a direction that is substantially parallel to along side direction of the slits. When the electric potential betweenthe electrodes is an off potential, liquid crystal molecules are alignedin a direction that is perpendicular to the long side direction of theslits. When an electric potential higher than the off potential isapplied between the electrodes, an electric field (horizontal electricfield) is generated in a direction perpendicular to the long sides ofthe slits, and liquid crystal molecules are rotated (horizontallyrotated) in a plane parallel to the substrate along the direction of theelectric field. By controlling the rotation angle of the liquid crystalmolecules, the amount of light transmission is controlled.

Note that, in addition to the FFS mode, an IPS (In-Plane Switching) modeis known as a configuration in which both the pixel electrode and thecommon electrode are provided in the element substrate.

Liquid crystal panels have been progressively reduced in size,thickness, and window frame width, and progressively added withfunctions, such as a touch panel. In accordance with the above, staticelectricity from the outside of the panels through a human body, or thelike, may cause a trouble in the panels.

For example, in the FFS mode, and the like, when an opposite substrate,which is opposed to an element substrate, is applied with staticelectricity and is electrostatically charged, there is a possibilitythat a vertical electric field is generated by the electrostatic chargeand, hence, an appropriate alignment control on the liquid crystal usingthe electrodes provided in the element substrate cannot be performed. Inthis case, for example, in a normally black liquid crystal panel, ablack display becomes whitish and the contrast is decreased. Inaddition, when a degree of whitish display is not uniform over theentire screen, display chrominance non-uniformity is observed.

As one of countermeasures to the above, there is a manner in which atranslucent conductive film is formed over the entire outer surface ofthe opposite substrate, and this translucent conductive film isconnected to a case or an FPC (Flexible Printed Circuit) terminal, thusreleasing the electrostatic charge to the ground electric potential(GND) of an external circuit, which is described in Japanese UnexaminedPatent Application Publication No. 9-105918.

Even with the above countermeasure, however, it has been found thatthere is a possibility that a sufficient electrostatic dischargeresistance cannot be obtained.

SUMMARY

An advantage of some aspects of the invention is that it provides aliquid crystal display device that improves electrostatic dischargeresistance.

A first aspect of the invention provides a liquid crystal displaydevice. The liquid crystal display device includes a first substrate, asecond substrate and liquid crystal. The first substrate includes pixelelectrodes, a peripheral circuit and a dummy wiring. The peripheralcircuit and the dummy wiring are provided outside a pixel area in whichthe pixel electrodes are arranged. The second substrate is opposed tothe first substrate through the liquid crystal. The second substrateincludes a translucent conductive film that is provided on an oppositeside of the second substrate to a side where the liquid crystal ispresent. The dummy wiring is located on an outer peripheral side of thesubstrates than the peripheral circuit and is provided independently ofthe peripheral circuit in terms of circuit. The dummy wiring is groundedoutside the first substrate.

A second aspect of the invention provides a liquid crystal displaydevice. The liquid crystal display device includes a first substrate, asecond substrate and liquid crystal. The first substrate includes pixelelectrodes, a peripheral circuit and a dummy wiring. The peripheralcircuit and the dummy wiring are provided outside a pixel area in whichthe pixel electrodes are arranged. The second substrate is opposed tothe first substrate through the liquid crystal. The second substrateincludes a translucent conductive film that is provided on an oppositeside of the second substrate to a side where the liquid crystal ispresent. The dummy wiring is connected to a power supply wiring througha protective resistance.

A third aspect of the invention provides a liquid crystal displaydevice. The liquid crystal display device includes a first substrate, asecond substrate and liquid crystal. The first substrate includes pixelelectrodes and a peripheral circuit. The peripheral circuit is providedoutside a pixel area in which the pixel electrodes are arranged. Thesecond substrate is opposed to the first-substrate through the liquidcrystal. The second substrate includes a translucent conductive filmthat is provided on an opposite side of the second substrate to a sidewhere the liquid crystal is present. The peripheral circuit includes apower supply wiring that is connected to a control terminal of a circuitelement through a protective resistance.

Here, the first substrate may further include at least one commonelectrode, wherein the translucent conductive film is maintained at apredetermined electric potential.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic view of a liquid crystal display device accordingto an embodiment of the invention.

FIG. 2 is a cross-sectional view of a liquid crystal panel according tothe embodiment of the invention.

FIG. 3 is a plan view that illustrates a first example of the liquidcrystal panel according to the embodiment of the invention.

FIG. 4 is a plan view that illustrates a second example of the liquidcrystal panel according to the embodiment of the invention.

FIG. 5 is a plan view that illustrates a third example of the liquidcrystal panel according to the embodiment of the invention.

FIG. 6 is a cross-sectional view that illustrates an influence of staticelectricity according to an existing FFS mode liquid crystal displaydevice.

FIG. 7 is a cross-sectional view that illustrates an influence of staticelectricity according to an existing FFS mode liquid crystal displaydevice.

DETAILED DESCRIPTION

Embodiments of the present application will be described below in detailwith reference to the drawings.

Before describing embodiments according to the invention, electrostaticdischarge resistance has been considered on the basis of variousevaluations. This will be described with reference to FIG. 6 and FIG. 7illustrating the cross-sectional views around peripheral portions of aliquid crystal display device.

As shown in FIG. 6 and FIG. 7 , in an existing FFS mode liquid crystaldisplay device 10Z, a first substrate 100Z and a second substrate 200Zare adhered to each other by a seal 304Z, and liquid crystal 302Z isheld between these substrates 100Z, 200Z. A circuit wiring group 104Z isarranged on a support substrate 102Z of the first substrate 100Z, and aninsulating film 114Z is arranged so as to cover the circuit wiring group104Z. Note that the circuit wiring group 104Z is schematically shown inthe drawing. A translucent conductive film 208Z is arranged on an outersurface of a support substrate 202Z of the second substrate 200Z, andthis translucent conductive film 208Z extends over the entire surface ofthe above outer surface, that is, to the outer periphery of the supportsubstrate 202Z, that is, to the outer periphery of the second substrate200 z. Note that, for example, by forming the translucent conductivefilm 208Z over the entire surface of a substrate, which includesmultiple number of unit substrates, and then separating the substrateinto the unit substrates, the translucent conductive film 208Z is formedso as to extend to the outer periphery of the second substrate 200Z.

When aerial discharge has been performed on the translucent conductivefilm 208Z, aerial discharge that is generated at the outer peripheralportion of the translucent conductive film 208Z, as shown in FIG. 6 ,was observed, and breakage was found in the circuit wiring group 104Zand circuit elements connected thereto. According to the above, it isconceivable that static electricity is transmitted from the outerperipheral portion of the translucent conductive film 208Z through theside of the outer peripheral portion of the second substrate 200Z to thecircuit wiring group 104Z. In this case, of the circuit wiring group104Z, static electricity tends to be transmitted to a circuit wiringcloser to the outer periphery of the substrate.

In addition, breakage also found in a circuit wiring remote from theouter periphery of the substrate and circuit elements connected thereto.It is conceivable that this breakage occurs because the electricpotential of the translucent conductive film 208Z rises due to staticelectricity that has entered the translucent conductive film 208Z, andthen the electric potential of the circuit wiring group 104Z rises dueto coupling with the electric potential rise of the translucentconductive film 208Z. That is, it is conceivable that the breakageoccurs due to the transmission of static electricity on the basis ofcoupling (see FIG. 7 ). Note that FIG. 7 is a schematic viewillustrating a state of coupling using the graphic symbols ofcapacitors. The coupling with the translucent conductive film 208Z tendsto occur as the area of wiring pattern is increased, that is, the widthand/or length, or the like, of wiring is increased. It is conceivablethat, for example, the coupling tends to occur with a power supplywiring that has a wide line width for reducing a resistance.

In addition, it has been found that breakage tends to occur more likelyin the circuit wiring that extends along the outer periphery of thesubstrate than in the circuit wiring that extends in a direction whichintersects with the outer periphery of the substrate.

An embodiment according to the invention will now be described withreference to the accompanying drawings. FIG. 1 is a schematic view of aliquid crystal display device 10 according to the embodiment. Note that,for easily understanding the drawings, components that are shown in FIG.1 and in the following drawings, when they are shown in the otherdrawings as well, are partially omitted.

As shown in FIG. 1 , the liquid crystal display device 10 is configuredto include a liquid crystal panel 12, a case 14 for the liquid crystalpanel 12, an FPC 16, and an external circuit 18. The liquid crystalpanel 12 is connected to the external circuit 18 through the FPC 16. Inplace of the FPC 16, various wiring bodies may be used. The followingwill exemplify a case where the liquid crystal panel 12 uses an FFSmode. Note that the liquid crystal panel 12 may be any one of atransmissive type liquid crystal panel, a reflective type liquid crystalpanel and a transflective type liquid crystal panel.

FIG. 2 is a cross-sectional view around an outer periphery of the liquidcrystal panel 12. The liquid crystal panel 12 is configured to include afirst substrate 100, a second substrate 200, liquid crystal 302 and aseal 304. The substrates 100, 200 are opposed to each other with apredetermined gap formed therebetween, and are adhered to each other atthe peripheral portions by the seal 304. The liquid crystal 302 is heldin a casing that is formed of the substrates 100, 200 and the seal 304.

The first substrate 100 includes a support substrate 102 that is, forexample, formed of a translucent substrate, such as glass, and isconfigured to include, on the inner surface side of the supportsubstrate 102, that is, on the side adjacent to the liquid crystal 302,insulating films 110, 112, at least one common electrode 116, pixelelectrodes 118, a peripheral circuit 150, and an alignment layer (notshown).

The common electrode 116 and the pixel electrodes 118 are pairedelectrodes that control the alignment of the liquid crystal 302, thatis, that drive the liquid crystal 302. The common electrode 116 iscommonly provided for a plurality of pixels, and each of the pixelelectrodes 118 is provided for each of the pixels. An electric potentialcorresponding to a display of each pixel is supplied to the pixelelectrode 118. Note that it may also be configured that the commonelectrode 116 is provided for each of the pixels and then a commonelectric potential is supplied to the common electrode 116. That is, theplurality of pixels are formed of the plurality of pixel electrodes 118and the at least one common electrode 116. Note that the outermostpixels, arranged all around, or more number of pixels, may possibly beused as dummy pixels that do not directly contribute to image display.

In the FFS mode liquid crystal panel 12, the electrodes 116, 118 bothare provided in the first substrate 100, and the electrodes 116, 118 arelaminated through the insulating film 112. The following will exemplifya case where the pixel electrodes 118 are arranged in an upper sidelayer, that is, on the side adjacent to the liquid crystal 302; however,the common electrodes 116 may be arranged in the upper side layer. Slits(not shown) are formed in each of the upper layer pixel electrodes 118,and the alignment of the liquid crystal 302 is controlled by an electricfield generated between the electrodes 116, 118 through the slits. Theelectrodes 116, 118 are, for example, formed of a translucent conductivefilm, such as ITO (Indium Tin Oxide).

The peripheral circuit 150 is a circuit that is arranged outside theelectrodes 116, 118 and the pixel area 13. Here, the pixel area 13 is anarea in which a plurality of the pixels are arranged. In other words,the plurality of pixels are arranged in the pixel area 13. Note that anarea for the dummy pixels also included in the pixel area 13. Theperipheral circuit 150 will be exemplified later.

The insulating films 110, 112 are, for example, formed of silicon oxide,silicon nitride, or the like, and are laminated on the support substrate102. Note that, for easy description, it exemplifies a case where theinsulating film 110 is located in a layer lower than the commonelectrode 116, that is, the layer adjacent to the support substrate 102,and the insulating film 112 is laminated on the insulating film 110;however, these insulating films 110, 112 are collectively called as aninsulating film 114. The insulating films 110, 112 each may be amonolayer film or may be a multilayer film. The alignment layer (notshown) is arranged to cover the pixel electrodes 118, and the alignmentlayer is treated with a rubbing process.

Note that FIG. 2 exemplifies a case where the peripheral circuit 150 isin contact with the support substrate 102 and is covered with theinsulating film 110; however, it may be configured so that theperipheral circuit 150 is embedded in the insulating film 114 formed ofa multilayer film and is not in contact with the support substrate 102.

The second substrate 200 includes a support substrate 202 that is, forexample, formed of a translucent substrate, such as glass, and isconfigured to include, on the inner surface side of the supportsubstrate 202, that is, on the side adjacent to the liquid crystal 302,a light shielding film 204, a color filter 206 and an alignment layer(not shown) and to include, on the outer surface side of the supportsubstrate 202, that is, on the side opposite to the liquid crystal 302,a translucent conductive film 208.

The support substrate 202 is opposed to the first substrate 100, and hasa size to be opposed to be opposed to the electrodes 116, 118 and theperipheral circuit 150. The light shielding film 204 is arranged on thesupport substrate 202. The light shielding film 204 extends over theentire surface on the support substrate 202 and has an opening at aposition opposite each of the pixel electrodes 118. Note that no openingis provided at a position opposite each of the dummy pixels. The lightshielding film 204 is, for example, formed a resin, or the like,containing black pigment. The color filter 206 is arranged on thesupport substrate 202 and is provided in each opening portion of thelight shielding film 204 so as to be opposed to the electrodes 116, 118.The alignment layer (not shown) is arranged to cover the light shieldingfilm 204 and the color filter 206, and the alignment layer is treatedwith a rubbing process.

The translucent conductive film 208 is arranged on the outer surface ofthe support substrate 202 and is opposed to the liquid crystal 302 andthe electrodes 116, 118, and the like, through the substrate 202. Thatis, the translucent conductive film 208 is provided in the secondsubstrate 200 and is located on an opposite side to a surface that is incontact with the liquid crystal 302. The translucent conductive film 208is maintained at an arbitrarily predetermined electric potential, forexample, a ground electric potential, and releases static electricity,which enters from the outside of the panel toward the second substrate200, thus preventing electrostatic charge of the second substrate 200.That is, the translucent conductive film 208 serves as a shielding film.Thus, it is possible to suppress a trouble due to electrostatic chargeof the second substrate 200, that is, for example, a decrease incontrast and chrominance non-uniformity. The translucent conductive film208 may be provided without patterning (without any gaps), or, as longas the body portion 208 a achieves a shielding effect against staticelectricity, it may be patterned to form a mesh.

The translucent conductive film 208 is, for example, formed of ITO, orthe like, and may be formed of any one of an inorganic material or anorganic material. The translucent conductive film 208 may be formed by aprocess, such as a sputtering process, a plasma CVD (Chemical VaporDeposition) process, a spin coating process, and a printing process. Thetranslucent conductive film 208 has a resistivity (sheet resistance) of,for example, 105Ω/□, which is preferably as low as possible. Note thatit exemplifies a case where the outer periphery of the translucentconductive film 208 extends to the outer periphery of the supportsubstrate 202, that is, to the outer periphery of the second substrate200; however, an area, in which the translucent conductive film 208 isarranged, is not limited to this.

The liquid crystal panel 12 will now be exemplified. FIG. 3 to FIG. 5are plan views that illustrate liquid crystal panels 12A to 12Caccording to first example to third example. Note that, for avoidingcomplicated drawing, an area outside the pixel area 13 is shown wide,and a connection state, or the like, of a wiring is partially omittedfrom the drawing.

In the liquid crystal panel 12A that is exemplified in FIG. 3 , theperipheral circuit 150 is configured to include an H scanner 152, a Vscanner 154, a V system circuit 156, a circuit 158, a COM wiring 162,wirings 164, 166, and the like.

The H scanner 152 and the V scanner 154 are circuits for scanning pixelshorizontally and vertically on a display screen. The V system circuit156 is, for example, a level shifter, and is connected to the V scanner154. The circuit 158 is, for example, a control circuit, a signalprocessing circuit, a detection circuit, and the like. Here, the circuit158 is connected to the scanners 152, 154. The COM wiring 162 is awiring that supplies an electric potential (common electric potential)to be applied to the common electrode 116 (see FIG. 2 ). The COM wiring162 extends from the end, which is connected to the FPC 16, toward thepixel area 13. Here, the COM wiring 162 extends from a portion near thepixel area 13 along three sides of the area 13. The wiring 164 is acontrol signal wiring for the V scanner 154 and extends from the end,which is connected to the FPC 16, toward the V scanner 154. The wiring166 is, for example, an input signal wiring to the V system circuit 156and extends from the end, which is connected to the FPC 16, toward the Vsystem circuit 156. Note that FIG. 3 exemplifies a case where the twowirings 166 are provided.

The liquid crystal panel 12A includes a dummy wiring 168 outside thepixel area 13. The dummy wiring 168 is arranged on the outer peripheralside of the substrate than the peripheral circuit 150 that is configuredto include the scanners 152, 154, and the like. The dummy wiring 168 isa wiring that is located on the outermost periphery among variouswirings of the liquid crystal panel 12A. In addition, the dummy wiring168 is not connected to the peripheral circuit 150, that is, the dummywiring 168 is provided independently of the peripheral circuit 150 interms of circuit. According to the above arrangement and connectionstate, the dummy wiring 168 does not intersect with the peripheralcircuit 150. The dummy wiring 168 surrounds the peripheral circuit 150.The dummy wiring 168 preferably avoids an intersection with theperipheral circuit 150 also at a portion connected to the FPC 16. Inthis case, the dummy wiring 168 does not constitute a closed path(closed loop) within the liquid crystal panel 12A, and both ends of thedummy wiring 168 are pulled out to the portion connected to the FPC 16.Both end portions of the dummy wiring 168 are connected through the FPC16 to the ground electric potential of the external circuit 18. Both endportions of the dummy wiring 168 may be connected to the ground electricpotential through a resistance of 10 kΩ to 1 mΩ.

According to the above configuration, even when static electricityenters from the outer peripheral portion of the translucent conductivefilm 208 over the side face of the support substrate 202 to the firstsubstrate 100, it is possible to flow the static electricity through thedummy wiring 168 to the ground electric potential of the externalcircuit 18. Thus, it is possible to suppress transmission of staticelectricity to the peripheral circuit 150, and electrostatic dischargeresistance is improved.

The dummy wiring 168 does not intersect with the peripheral circuit 150.For this reason, static electricity entering the dummy wiring 168 issuppressed from being transmitted to the peripheral circuit 150 due tocoupling. Thus, electrostatic discharge resistance is improved.

Because the dummy wiring 168 is connected to the ground electricpotential of the external circuit 18, the ground electric potential maypossibly rise when static electricity enters the dummy wiring 168.However, in terms of a signal, a power supply electric potential, or thelike, to which a voltage value is set relatively to the ground electricpotential as a reference, an influence of a rise in ground electricpotential is suppressed. Therefore, electrostatic discharge resistanceis improved in comparison with a case where the dummy wiring 168 is, forexample, connected to the ground electric potential of the liquidcrystal panel 12A.

In the liquid crystal panel 12B as exemplified in FIG. 4 , theperipheral circuit 150 is configured to include the H scanner 152, the Vscanner 154, the V system circuit 156, the circuit 158, the COM wiring162, the wirings 164, 166, a power supply wiring 169, and the like. Inaddition, the liquid crystal panel 12B includes a dummy wiring 170 andprotective resistances 180. Note that the same reference numerals areassigned to the same or similar components described above, and adescription there of is omitted.

The power supply wiring 169 is, for example, a wiring that supplies apower supply electric potential Vss, and extends from the end, which isconnected to the FPC 16, to be connected to the V system circuit 156 andthe H scanner 152. Note that the electric potential Vss is, for example,supplied through the V system circuit 156 to the V scanner 154 andsupplied through the H scanner 152 to the circuit 158.

The dummy wiring 170 is connected through the resistance 180 to thepower supply wiring 169, and extends around the panel and then isconnected through the other resistance 180 to the power supply wiring169 again. Here, the dummy wiring 170 is located on the outermostperiphery than various wirings of the peripheral circuit 150. The dummywiring 170 surrounds the scanners 152, 154, the V system circuit 156,the circuit 158, and the like. The dummy wiring 170 extends along theouter periphery of the substrate to form a closed loop in the liquidcrystal panel 12B.

The protective resistances 180 have a resistance value of, for example,10 kΩ to 10 MΩ. The protective resistances 180 may be, for example,formed by using a silicon film.

According to the above configuration, even when static electricityenters from the outer peripheral portion of the translucent conductivefilm 208 over the side face of the support substrate 202 to the dummywiring 170, which is the outermost wiring of the first substrate 100,the static electricity is consumed in the protective resistances 180. Inaddition, even when static electricity entering the translucentconductive film 208 causes fluctuation in electric potential of thedummy wiring 170 due to coupling, the fluctuation in electric potentialis consumed by the protective resistances 180. For this reason, theentered static electricity is suppressed from being transmitted to acircuit element, such as the scanner 152. Thus, electrostatic dischargeresistance is improved.

In the liquid crystal panel 12C as exemplified in FIG. 5 , theperipheral circuit 150 includes, in addition to the above configurationexemplified in FIG. 4 , a power supply wiring 172 and a protectiveresistance 182. The power supply wiring 172 and the protectiveresistance 182 are arranged inside the above closed loop portion of thedummy wiring 17 in the liquid crystal panel 12C. Note that the samereference numerals are assigned to the same or similar componentsdescribed above, and a description thereof is omitted.

The power supply wiring 172 is a wiring that supplies a power supplyelectric potential used in the V scanner 154 and in the circuit 158.Note that the power supply electric potential may be an electricpotential that is generated in the liquid crystal panel 12C, or may bean electric potential that is supplied from the external circuit 18 (seeFIG. 1 ), or the like. The power supply wiring 172 passes through the Vscanner 154 and extends along the outer periphery of the substrate, andthen is connected through the protective resistance 182 to the circuit158. The protective resistance 182 has a resistance value of, forexample, 10 kΩ to 10 MΩ. The protective resistance 182 may be, forexample, formed by using a silicon film.

The circuit 158 in the liquid crystal panel 12C uses the above powersupply electric potential that is supplied by the power supply wiring172 as a control signal. For example, the circuit 158 may be a signalprocessing circuit, a detection circuit, or the like, that is shared bythe H scanner 152 and the V scanner 154. When the power supply electricpotential is supplied through the power supply wiring 172, the circuit158 is switched to a circuit for the V scanner 154. When no power supplyelectric potential is supplied, the circuit 158 is switched to a circuitfor the H scanner 152. The thus switching may be, for example, achievedby using a switching element, such as a MOS (Metal Oxide Semiconductor)transistor, and the power supply wiring 172 is connected to a controlterminal of the switching element, that is, for example, the gate of theMOS transistor.

Particularly, the protective resistance 182 is connected in the powersupply wiring 172 in a midway of the path from the V scanner 154 to thecontrol terminal, and the protective resistance 182 is provided upstreamof the control terminal.

According to the above configuration, even when static electricityentering the translucent conductive film 208 causes fluctuation inelectric potential of the power supply wiring 172 due to coupling, thefluctuation in electric potential is consumed by the protectiveresistance 182. In addition, even when static electricity enters fromthe outer peripheral portion of the translucent conductive film 208 overthe side face of the support substrate 202 to the power supply wiring172 of the first substrate 100, the static electricity is consumed inthe protective resistance 182. For this reason, the entered staticelectricity is suppressed from being transmitted to the control circuitof the switching element. Thus, electrostatic discharge resistance isimproved.

Here, in light of the evaluation that static electricity tends to betransmitted to a wiring that extends along the outer periphery of thesubstrate, electrostatic discharge resistance is reliably improved byconnecting the protective resistances 180, 182 to the wirings 170, 172,respectively.

In addition, the wirings 170, 172 to which the protective resistances180, 182 are connected and the dummy wiring 168 may be variouslycombined, and, thereby, it is possible to further improve electrostaticdischarge resistance. Furthermore, the dummy wiring 168 and the wirings170, 172, to which the protective resistances 180, 182 are connected,are effective against static electricity that enters the first substrate100 without passing through the translucent conductive film 208.

Moreover, the above description exemplifies the FFS mode in which theelectrodes 116, 118 that drive the liquid crystal 302 are laminatedthrough the insulating film 112. However, it may be configured as an IPSmode in which both electrodes 116, 118 are arranged in the same layer(for example, on the insulating film 112). When in the IPS mode, forexample, the electrodes 116, 118 having a comb-shaped pattern arearranged so that the comb-shaped portions are alternately meshed witheach other. In addition, the above configured liquid crystal displaydevice 10 may be applied to a liquid crystal display device, such as aTN (Twisted Nematic) mode, in which the common electrode 116 is opposedto the pixel electrodes 118 through the liquid crystal 302.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The application is claimed as follows:
 1. A display device comprising: afirst insulating layer including pixel electrodes and a common electrodein a pixel area and including a peripheral circuit and a dummy wiring ina peripheral area surrounding the pixel area; a second insulating layerincluding a conductive film provided at an opposite side of the secondinsulating layer to the first insulating layer side, the conductive filmoverlapping the pixel area, the peripheral area, and the dummy wiring inplan view; and a pixel layer between the first insulating layer and thesecond insulating layer, wherein the peripheral circuit includes acommon wiring supplying a common electric potential to the commonelectrode, the common wiring being separated from the dummy wiring, thedummy wiring is located between the peripheral circuit and an outermostedge of the first insulating layer at the outermost edge of the firstinsulating layer, the dummy wiring is made of a continuous metal layersurrounding the pixel area and peripheral circuit on at least threesides of the first insulating layer and is connected to a referencepotential outside the first insulating layer, and the dummy wiring isprovided to discharge electric potential rise on the first insulatinglayer that occurs due to coupling with electric potential rise of theconductive film on the second insulating layer.
 2. The display deviceaccording to claim 1, wherein the conductive film is maintained at apredetermined electric potential.
 3. The display device according toclaim 1, wherein the dummy wiring does not intersect with the peripherycircuit.
 4. The display device according to claim 1, wherein the dummywiring surrounds the outer periphery of the side of the first insulatinglayer and does not constitute a closed path, both ends of the dummywiring are extended to a portion that connects with the external wiringand are connected to the reference potential of the external circuitthrough the external wiring.
 5. The display device according to claim 1,wherein the reference potential outside the first insulating layer isseparate from a reference potential of the display device.
 6. Thedisplay device according to claim 1, wherein the dummy wiring has twoends, wherein each end is connected to the reference potential outsidethe first insulating layer.
 7. The display device according to claim 1,wherein the dummy wiring surrounds three sides of the first insulatinglayer and surrounds at least a part of a fourth side.
 8. The displaydevice according to claim 1, wherein the dummy wiring is covered with athird insulating layer.
 9. A display device comprising: a firstinsulating layer including pixel electrodes and a common electrode in apixel area and including a peripheral circuit and a dummy wiring in aperipheral area surrounding the pixel area; a second insulating layerincluding a conductive film provided at an opposite side of the secondinsulating layer to the first insulating layer side, the conductive filmoverlapping the pixel area, the peripheral area, and the dummy wiring inplan view; and a pixel layer between the first insulating layer and thesecond insulating layer, wherein the peripheral circuit includes acommon wiring supplying a common electric potential to the commonelectrode, the common wiring being separated from the dummy wiring, thedummy wiring is located between the peripheral circuit and an outermostedge of the first insulating layer at the outermost edge of the firstinsulating layer, the dummy wiring is made of a continuous metal layersurrounding the pixel area and peripheral circuit on at least threesides of the first insulating layer and is connected to a referencepotential outside the first insulating layer, the dummy wiring isprovided to discharge electric potential rise on the first insulatinglayer that occurs due to coupling with electric potential rise of theconductive film on the second insulating layer, the dummy wiring iscovered with a third insulating layer, and the common electrode islocated on the side of the pixel layer of the third insulating layer.10. The display device according to claim 9, wherein the commonelectrode is covered with a fourth insulating layer.
 11. The displaydevice according to claim 10, wherein the pixel electrodes are locatedon the side of the pixel layer of the fourth insulating layer.
 12. Thedisplay device according to claim 1, further comprising: a seal memberprovided between the first insulating layer and the second insulatinglayer to seal the pixel layer, wherein the dummy wiring overlapping theseal member in plan view.
 13. The display device according to claim 9,wherein the conductive film is maintained at a predetermined electricpotential.
 14. The display device according to claim 9, wherein thedummy wiring does not intersect with the periphery circuit.
 15. Thedisplay device according to claim 9, wherein the dummy wiring surroundsthe outer periphery of the side of the first insulating layer and doesnot constitute a closed path, both ends of the dummy wiring are extendedto a portion that connects with the external wiring and are connected tothe reference potential of the external circuit through the externalwiring.
 16. The display device according to claim 9, wherein thereference potential outside the first insulating layer is separate froma reference potential of the display device.
 17. The display deviceaccording to claim 9, wherein the dummy wiring has two ends, whereineach end is connected to the reference potential outside the firstinsulating layer.
 18. The display device according to claim 9, whereinthe dummy wiring surrounds three sides of the first insulating layer andsurrounds at least a part of a fourth side.
 19. The display deviceaccording to claim 9, further comprising: a seal member provided betweenthe first insulating layer and the second insulating layer to seal thepixel layer, wherein the dummy wiring overlapping the seal member inplan view.